This application claims the priority of application Ser. No. H11-315311, filed Nov. 5, 1999 in Japan, the subject matter of which is incorporated here by reference.
The present invention relates to a molding die set used for fabricating a semiconductor apparatus, and to a method for fabricating a semiconductor apparatus using such a molding die set.
According to a conventional technology, surface voids and/or inner voids may be made in a semiconductor package when a semiconductor apparatus, such as IC and LSI, is resin-molded using a thermosetting resin. Thus molded package is treated as defective. In order to prevent voids in a semiconductor package, a mold chase unit is designed to be able to reduce the pressure therein.
Accordingly, an object of the present invention is to provide a molding die set whereby a molding process can be carried out at a desirable pressure-reduced condition in cavities.
Another object of the present invention is to provide a semiconductor device package which is fabricated to reduce voids generated in a molded package.
Additional objects, advantages and novel features of the present invention will be set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
According to a first aspect of the present invention, a molding die set includes a first molding die which comprises cavities and a parting surface; a second molding die which comprises cavities and a parting surface arranged to face the first molding die; and an O-ring supported on the first molding die to surround the cavities and to have a peripheral line which does not extend outwardly from the parting surface.
In the first aspect of the present invention, the second molding die may have a projection which extends outwardly from the parting surface so that the projection is in contact with the O-ring when the first and second molding dies are clamped to each other. In one case, the first molding die may have a groove in which the O-ring is completely contained, and the projection of the second molding die may have an end which goes into the groove to be in contact with the O-ring when the first and second molding dies are clamped to each other. In another case, the first molding die may have a groove in which the O-ring is supported, the O-ring partially being exposed from the groove toward the second molding die, and the projection may have an end which is wider than the groove so that an outer surface of the projection is in contact with the exposed portion of the O-ring when the first and second molding dies are clamped to each other. In still another case, the first molding die may have a side with a groove in which the O-ring is supported, and the projection may have an inner side which is in contact with the O-ring when the first and second molding dies are clamped to each other.
According to a second aspect of the present invention, a molding die set includes a molding die which comprises cavities, ejector holes each of which extends to the corresponding cavity; ejector pins each of which is movably arranged inside the corresponding ejector hole; and sealing members each of which air-seals the corresponding ejector hole.
In the second aspect of the present invention, the sealing members may be O-rings each of which is arranged to surround the corresponding ejector pin. In one case, the molding die set may further include a cavity block comprising the cavities; and a cavity holder supporting the cavity block. Each of the ejector holes is formed through the cavity block and cavity holder to have a wider diameter portion in which the O-ring is set. Each of the ejector pins may have a flange which is in contact with the corresponding O-ring to improve air sealing function.
According to a third aspect of the present invention, a molding die set includes a molding die which comprises cavities, pressure reducing paths formed around the cavities; and a plurality of pressure reducing ports connected to the pressure reducing paths, each of the pressure reducing ports being arranged so as to minimize the distance from the farthest cavity.
In the third aspect of the present invention, the cavities may be arranged on two parallel lines in each of the first and second molding dies, the pressure reducing paths are arranged at the both sides of the lines of cavities, and the pressure reducing ports are arranged at least at the center of each of the pressure reducing paths.
A semiconductor device package according to the present invention is fabricated using one of the above described molding die sets of the first to third aspects of the present invention.